[1.12.x] MissingHistory v1.9.3: Handy parts to complement Making History.

[fragtzack]

Be nice to have a 1.875 liquid fuel only tank for nuke engine. Well aware of ISP, but generally prefer to not use mods if can do with stock tools. Funny thing, Missing History doesn't seem like a mod to me

 

The booster engine included with Missing History seems a bit too good compared to all the new boosters with 1.8.0 Moar Boosters update. THK Pollux has the best stats of all the boosters, could use a tad nerf.

[RealKerbal3x]

4 hours ago, fragtzack said:

Be nice to have a 1.875 liquid fuel only tank for nuke engine. Well aware of ISP, but generally prefer to not use mods if can do with stock tools. Funny thing, Missing History doesn't seem like a mod to me

Well, you could give another one of Snark’s mods a go:

It enables switching fuel tanks between LF and LFO. It’s pretty lightweight, too.

[jimmymcgoochie]

I just downloaded this mod, but the reskinned Kerbodyne tanks are horribly mangled when I switch to the black and white look- it's like the original pattern and the grey and orange look from the 1.875m tanks are trying to be in the same place at the same time, and it looks extremely glitchy.

[Snark]

1 hour ago, jimmymcgoochie said:

I just downloaded this mod, but the reskinned Kerbodyne tanks are horribly mangled when I switch to the black and white look- it's like the original pattern and the grey and orange look from the 1.875m tanks are trying to be in the same place at the same time, and it looks extremely glitchy.

Known issue, will be releasing an update to address it soon. In the meantime you can fix it by deleting three files from the "rescaled" folder of MissingHistory: Size3SmallTank.cfg, Size3MediumTank.cfg, and Size3LargeTank.cfg.

[Snark]

8 hours ago, fragtzack said:

The booster engine included with Missing History seems a bit too good compared to all the new boosters with 1.8.0 Moar Boosters update. THK Pollux has the best stats of all the boosters, could use a tad nerf.

I assume you're talking about the Stomper SRB?

Yes, it has a better TWR than the new boosters in KSP 1.8, by quite a bit... but in my opinion, that's not because it's OP, but rather because those new boosters are abysmal. Their TWR is way lower than even the Kickback, which itself has a far lower TWR than all the smaller sized SRBs.

I balanced the Stomper fairly carefully to make the numbers scale reasonably from the Thumper, and in general I've been pretty happy with it, so don't have any plans to nerf it any time soon.

[OhioBob]

On 11/2/2019 at 8:11 AM, Snark said:

Yes, it has a better TWR than the new boosters in KSP 1.8, by quite a bit... but in my opinion, that's not because it's OP, but rather because those new boosters are abysmal. Their TWR is way lower than even the Kickback, which itself has a far lower TWR than all the smaller sized SRBs.

In fairness to Squad, the new larger SRBs should have lower TWR than the Kickback.  Though I agree that the Kickback's TWR (and the Thumper's) is lower than it probably should be.

SRBs can use different fuel grain geometries and propellant formulations to alter how fast they burn, and hence how much thrust they produce.  But if the burn rate remain unchanged, then thrust becomes mainly just a function of the area of the exposed burn surface.  Obviously as a SRB get longer, the burn surface increases proportional to length.  And as a SRB gets wider, the size of the central channel gets larger.  As long as the basic geometry of the grain is not altered, the area of the burn surface will increase proportional to the diameter.  So the end result of this is that thrust is proportional to length*diameter.

However, as a SRB gets wider, the cross-sectional area of the booster increases proportional to the diameter squared.  This means that the mass of a SRB is proportional to length*diameter^2.  And since TWR is thrust divided by weight, we see from these relationships that TWR is proportional to 1/diameter.  So all other things being equal, a wider SRB means lower TWR.

Of course, as I said, there are other things that can be done, such as increasing burn rate, to increase thrust and TWR.  But generally speaking, I don't think the performance of the new SRBs is really out of line in comparison to the other SRBs.  By some measures the performance may be abysmal, but that doesn't make it unrealistic.  It's just that, contrary to what some may believe, making a SRB wider is not the answer if you want a high TWR.
 

Edited November 4, 2019 by OhioBob

[Snark]

2 hours ago, OhioBob said:

By some measures the performance may be abysmal, but that doesn't make it unrealistic.

Oh, sure-- and no quibbles at all with your excellent explanation, thank you! 

To be clear, my comments weren't at all based on "realism", simply about playability.  The big new SRBs simply have a much lower TWR than the Kickback, which itself has a much lower TWR than the smaller SRBs.

This makes the SRBs enforce a fairly draconian upper limit on the TWR of large vessels, if they're using the SRBs for primary lift.  For example, I happen to like to launch my ships with fairly high TWR on the pad, i.e. approaching 2.0.  I have no trouble at all in KSP building even very large ships with that TWR; the Mammoth does a fantastic job at 3.75m, and clusters of Mainsails or Mastodons work just fine for 5m builds.  But when the SRB itself tops out at barely over 2, that means it can't help much with lifting unless the overall rocket's TWR is considerably lower.

There's nothing wrong with low TWR, nor am I suggesting that higher is in any way "better".  It just happens to be the way I like to play, is all.

One of the things I've always liked about KSP is its design flexibility, and the way that it enables people with very different play styles to play more or less how they want to.  People who like low launchpad TWR can build that way.  People who like high launchpad TWR can build that way, too.  But the big SRBs are pretty much limited to the low-TWR end of the large-craft spectrum, which means that I end up not using them as much as I'd like.  Which is a pity, because they're cool. 

[OhioBob]

I think one of the biggest problems is that the Kickback's thrust is way too low.  (About 1200 kN seems more reasonable to me given its size and ISP.)  If the larger SRBs were then sized correctly in proportion to a more powerful Kickback, they too would have a higher TWR.  The TWR still wouldn't be great, but it would be better and more useful.

When I did my SRB mod I didn't even bother with 2.5-m SRBs just because of the low TWR issue.  I didn't think they were that useful, so I stopped at 1.875-m.

[Snark]

1 hour ago, OhioBob said:

I think one of the biggest problems is that the Kickback's thrust is way too low.

^ Very much this!  It's why I've never used Kickbacks all that much.

I like the new SRBs enough that I'll probably end up writing a ModuleManager patch for my own private consumption that just boosts their thrust without affecting their other stats (i.e. they'll still provide the same amount of total impulse, just burn through their fuel load faster).  Might as well give the Kickback some treatment as well, while I'm at it.  (No worries, folks, I'm not planning on rejiggering things in MissingHistory, I'm just talking about my own private gameplay).

I don't want to radically rebalance the game, just make the large SRBs a bit more attractive to use so that I'll actually use them.  I'm thinking like a 15% boost to the Kickback's thrust, and maybe 25% to the Pollux / Thoroughbred / Clydesdale, something like that.  I'll need to tinker with it a bit to find the sweet spot, i.e. where they're powerful enough that I'll actually use them, but not so powerful that I stop using LFO engines for boost.

...Now if only the Pollux had some gimbal on it...

[Jognt]

59 minutes ago, Snark said:

^ Very much this!  It's why I've never used Kickbacks all that much.

I like the new SRBs enough that I'll probably end up writing a ModuleManager patch for my own private consumption that just boosts their thrust without affecting their other stats (i.e. they'll still provide the same amount of total impulse, just burn through their fuel load faster).  Might as well give the Kickback some treatment as well, while I'm at it.  (No worries, folks, I'm not planning on rejiggering things in MissingHistory, I'm just talking about my own private gameplay).

I don't want to radically rebalance the game, just make the large SRBs a bit more attractive to use so that I'll actually use them.  I'm thinking like a 15% boost to the Kickback's thrust, and maybe 25% to the Pollux / Thoroughbred / Clydesdale, something like that.  I'll need to tinker with it a bit to find the sweet spot, i.e. where they're powerful enough that I'll actually use them, but not so powerful that I stop using LFO engines for boost.

...Now if only the Pollux had some gimbal on it...

Just saying, but I’d be totally appreciative if you could off-hand mention your final tweaked SRBs somewhere. (Yes, I’m lazy)

More on-topic: Did you catch that cfg I posted earlier about the .625m structural fuselage? I know it’s been a long time between you mentioning it and me posting it so I totally get it if you changed your mind. Just checking.  

[OhioBob]

19 hours ago, Snark said:

^ Very much this!  It's why I've never used Kickbacks all that much.

I like the new SRBs enough that I'll probably end up writing a ModuleManager patch for my own private consumption that just boosts their thrust without affecting their other stats (i.e. they'll still provide the same amount of total impulse, just burn through their fuel load faster).  Might as well give the Kickback some treatment as well, while I'm at it.  (No worries, folks, I'm not planning on rejiggering things in MissingHistory, I'm just talking about my own private gameplay).

I don't want to radically rebalance the game, just make the large SRBs a bit more attractive to use so that I'll actually use them.  I'm thinking like a 15% boost to the Kickback's thrust, and maybe 25% to the Pollux / Thoroughbred / Clydesdale, something like that.  I'll need to tinker with it a bit to find the sweet spot, i.e. where they're powerful enough that I'll actually use them, but not so powerful that I stop using LFO engines for boost.

...Now if only the Pollux had some gimbal on it...

I don't know if it would help you or not, but for my BetterSRBs mod I did a complete rebalancing of all SRBs, which you might be able to use for inspiration.  I got more complex with it than you seem to be interested in, so I'll spare you all the unnecessary detail.  But the basis of my thrust calculations really came down to burn time, with burn time being a function of SRB diameter:

Diameter  Burn time
0.625 m     18 s
1.250 m     36 s
1.875 m     54 s
2.500 m     72 s

And if we know the burn time, everything else follows easily.  For instance, the Kickback contains 19.5 t of propellant with a vacuum ISP of 220 s.  Therefore the average vacuum thrust is,

19.5 / 36 * 220 * 9.80665 = 1169 kN

If this were done for all the large SRBs, we'd have:

SRB name       Old thrust  New thrust     TWR   % change
Thumper           300 kN      352 kN     4.69     +17%
Kickback          670 kN     1169 kN     4.97     +74%
Pollux           1300 kN     1777 kN     3.52     +37%
Thoroughbred     1700 kN     1880 kN     2.74     +11%
Clydesdale       3300 kN     3937 kN     2.79     +19%

If that is still too low for the 2.5-m SRBs, you can always use a shorter burn time, which can be justified by assuming changes to propellant grain and formula.

(From the above numbers it's easy to see just how out underpowered the Kickback really is.)

(edit)  Sorry if this is going too far off topic.  I'll stop now.
 

Edited November 5, 2019 by OhioBob

[linuxgurugamer]

Or you could try this:

It now has sizes going up to 3.75m.

Final beta now.  Next version will have the ability to change the thrust curves by selecting a grain.

The full release will be for both 1.7.3 and 1.8

Edited November 5, 2019 by linuxgurugamer

[JAFO]

8 hours ago, Snark said:

I like the new SRBs enough that I'll probably end up writing a ModuleManager patch for my own private consumption that just boosts their thrust without affecting their other stats (i.e. they'll still provide the same amount of total impulse, just burn through their fuel load faster).  Might as well give the Kickback some treatment as well, while I'm at it.

If you're going to do that, at least please consider adding your patch to the Community Database of Module Manager Patches for Stock KSP.

[SingABrightSong]

I don't believe it's mentioned anywhere, but the Missing History parts do appear to have built-in compatibility with Indicator Lights, as one would expect.

[RealKerbal3x]

1 minute ago, SingABrightSong said:

I don't believe it's mentioned anywhere, but the Missing History parts do appear to have built-in compatibility with Indicator Lights, as one would expect.

Yes, probably because Missing History and Indicator Lights are both authored by Snark 

[Snark]

Hi folks,

Just a note to let you know that I've released MissingHistory version 1.8.1. This update removes the orange 3.75m tank variants that the mod previously provided.  This is because KSP 1.8 added stock variants of these tanks, meaning that my version was, 1. no longer needed, and 2. actually causing visual glitches for these tanks.

Thanks to @webward for reporting the issue! 

On 11/4/2019 at 2:54 PM, Jognt said:

More on-topic: Did you catch that cfg I posted earlier about the .625m structural fuselage? I know it’s been a long time between you mentioning it and me posting it so I totally get it if you changed your mind. Just checking.  

Thanks for bringing it up!  Sorry, I totally dropped the ball and forgot to get back to you when you posted.

I appreciate the work, but after having thought things over, I don't think I'm prepared to risk doing anything with the structural tubes.  Even when I'm spoon-fed a solution such as you so generously did, it's still not zero risk.  Variable drag cubes have been a notoriously finicky/buggy area in KSP, and the config is a nightmare (for example, I note that the config you provided doesn't cover multiple variants), and debugging aero behavior is a real pain (hard to tell "is this part generating the drag it should" easily).  Adding a solution like this means potentially having to go through cycles of bug reports / investigation / attempted fixes an indeterminate number of times an indeterminate time in the future, as users potentially run into bugs that I might have missed in the (very cursory) testing I do before release.

Coupled with this is the fact that I myself never ever use the structural tubes for any reason whatever, which reduces my motivation to want to add a potentially-risky part.  Not that I have anything against the idea of the tubes, I think it's great and would love to use them.  But their aerodynamics are so egregiously extravagantly hideous (incredibly high drag added to any vehicle they're on-- I mean, like, buggy draggy) that I just can't bring myself to ever use 'em.

Anyway, high risk plus (for me) low benefit means I don't think I'm prepared to make that tradeoff, at least not right now.  If Squad ever revises the way aero is handled for variants in general and for the structural tubes in particular, such that no special config work is needed and the parts are fully usable, then I might reconsider this decision. 

[Idleness]

Is there much/any overlap between the parts introduced here and Restock/Restock+ and other NF mods authored by Nertea and co?

[Snark]

9 minutes ago, Idleness said:

Is there much/any overlap between the parts introduced here and Restock/Restock+ and other NF mods authored by Nertea and co?

No idea, I don't run those mods myself and am not familiar with their content.

On 11/4/2019 at 2:54 PM, Jognt said:

Just saying, but I’d be totally appreciative if you could off-hand mention your final tweaked SRBs somewhere.

OK, I've added it to my grab-bag-of-gameplay-tweaks repository, here:

• StrongerBigSRBs.cfg

Enjoy! 

On 11/4/2019 at 10:09 PM, JAFO said:

If you're going to do that, at least please consider adding your patch to the Community Database of Module Manager Patches for Stock KSP.

Good idea, done.

[SingABrightSong]

6 hours ago, Idleness said:

Is there much/any overlap between the parts introduced here and Restock/Restock+ and other NF mods authored by Nertea and co?

Significant overlap, as it would happen, as both mods implement Porkjet's Part Overhaul, in addition to adding variants to existing parts. I'd estimate that the overlap approaches an eclipse

[Idleness]

Thanks for clearing that up.  I had suspected as much but sometimes it's difficult to compare parts catalogues.

[Yankee42Kid]

Any chance you could add the orange texture for the 5m part.

[RealKerbal3x]

53 minutes ago, Yankee42Kid said:

Any chance you could add the orange texture for the 5m part.

Have a look on the previous page. I suggested it. Snark tried rescaling the 2.5m tank models and because of differences in the proportions of the 2.5m and 5m tanks it didn’t work.

[Yankee42Kid]

On 12/14/2019 at 4:18 PM, RealKerbal3x said:

Have a look on the previous page. I suggested it. Snark tried rescaling the 2.5m tank models and because of differences in the proportions of the 2.5m and 5m tanks it didn’t work.

Thanks

[catmanoff_]

This mod is cool, thanks to author for all!

[jimmymcgoochie]

On 11/6/2019 at 7:50 PM, Idleness said:

Is there much/any overlap between the parts introduced here and Restock/Restock+ and other NF mods authored by Nertea and co?

As of Restock+ v1.0 and above, substantial overlap- Restock+ includes 1.875m versions of almost all the parts included in Missing History (probe core, reaction wheel, battery, SRB etc.) and I'm fairly sure that with both MH and Restock+ you end up with two Pugs and two Valiants in different places on the tech tree.

Personally, I use the Restock versions as they're consistent with each other for the most part whereas MH parts are built around the stock part appearances so look out of place with everything else Restock-ified. However, some parts from MH aren't found anywhere else- the 1.25m engine plate and the 2.5-1.875m short tank and the part tweaks for cheetah (that dangling node annoyed me too) and the FL-A10 conversion into a fuel tank (surprisingly brilliant for small rockets)- and so I kept those parts. If you're not using Restock, use Missing History in its entirety; if you are using Restock, Restock+ will cover most of the bases but MH still has a few unique things to offer.

Near Future mods have almost no overlap with MH, but Kerbal Atomics adds a 0.625m nuclear engine as well with pretty good stats- KA uses liquid hydrogen for nuclear engines and will switch most other nuclear engines to use it too, but this can be disabled with a patch that switches KA to use liquid fuel instead with reduced ISP.